Residents in Fort Collins, Colorado, have been left startled by sightings of wild rabbits with unusual "tentacle and horn-like" growths.
Wildlife officials have addressed concerns after images shared on social media showed animals with black, spiky growths around their mouths and faces.
They have confirmed that the strange condition is caused by a virus, and while it may look terrifying, it poses no danger to humans or pets.
According to Colorado Parks and Wildlife (CPW), the growths seen on the rabbits are wart-like tumors caused by the Shope papilloma virus, which specifically affects rabbits.
These tumors, which can sometimes become malignant, typically appear on the animal's head, face, or mouth, and are spread by biting insects like mosquitoes or ticks.
While the virus does not spread to humans, dogs, or other animals, CPW advises the public to avoid approaching or touching infected rabbits.
Local resident Susan Mansfield, who spotted a rabbit with the condition, described the growths as “black quills or black toothpicks sticking out all around his or her mouth," per KBTX.
She said she’s seen the same rabbit return to her yard for two years in a row, with the growths becoming more noticeable each time.
“I thought he would die off during the winter, but he didn’t,” she said. “He came back a second year, and it grew.”
Another resident described the appearance as a “scabbiesh-looking growth” covering the rabbit’s face, sparking fears that the animals could be carrying the plague or another dangerous illness.
CPW clarified that the virus is believed to be relatively common among wild rabbit populations and is comparable to benign cancerous cells.
While the growths typically don’t harm the animals directly, they can cause issues if they interfere with critical areas like the eyes or mouth. In some cases, wildlife experts said the growths may even resolve on their own.
In domestic rabbits, treatment options may include surgical removal and regular veterinary monitoring.
Despite the unsettling appearance of the affected animals, wildlife officials stressed the importance of leaving them alone and allowing nature to take its course.
The agency has also strongly advised against trying to feed, help, or handle any infected rabbits, even if they appear friendly or harmless.
So while these "horned" rabbits may look like something out of a sci-fi nightmare, officials say the best response is simple: do not interfere.